My dear P.M.,
The question of the future of this External Affairs service has been rather on my mind. I think the real difficulty about keeping people in the service is that of the lack of appointment for promotion. You may say that it would be possible to make opportunities for promotion from the External Affairs service into other branches of the Australian Civil Service-but people of the type you want in this service will not want to go into the ordinary administrative services-they will tend to become specialists on foreign affairs and would probably be unsuitable for ordinary administrative work.
The External Affairs service is now composed of 5 or 6 men, and the top two jobs are worth 1,000 a year-this is small inducement to get good men permanently. It tends to attract good men for a few years' interesting experience and it is not a good thing to have new men floating in and out.
The solution is not simple and I am far from suggesting that new and well-paid posts should be created merely to provide opportunity for lucrative promotion.
Allen Leeper's  idea from the start has been that we should institute entry by examination and selection on exactly the same lines as entry into the British Diplomatic Service, and that we should approach the Foreign Office with the idea of having a system of free exchange of officers between our External Affairs service and the British Foreign service. On talking to him in Vienna lately, I find he is unchanged in his views on this point.
I don't think this would work. We would, no doubt, be glad enough to have the privilege of members of our External Affairs service exchanging temporarily with the British Diplomatic Service for experience and promotion, but I cannot imagine the reverse happening. It would be quite inappropriate for members of the British Diplomatic Service to be Director of External Affairs at Canberra, to be Liaison Officer here in London, or even (looking into the future) acting as Australian Counsellors at Washington or Tokyo. The very point of our External Affairs service is that the personnel should be Australians and should know Australia, so that they can instinctively take the Australian point of view.
No; I think we will have to put up with the fact that for the next ten years or so we are likely to have good men coming into the External Affairs service for 2 or 3 or 4 years and then going out.
This is not a good thing admittedly, hut if we have men of a good type, the risk of their making subsequent use of the information they gain is small. And as the External Affairs service seems likely to grow naturally, then the position will gradually right itself, and it may be expected to live and thrive as a service completely separate from the British Diplomatic Service. 
I am, Yours sincerely, R. G. CASEY